CMake/Modules/FindPackageHandleStandardArgs.cmake
Yury G. Kudryashov 26015baba3 FindPackageHandleStandardArgs: fix documentation
State explicitly what CONFIG_MODE argument does.
2012-01-20 09:09:47 -05:00

261 lines
11 KiB
CMake

# FIND_PACKAGE_HANDLE_STANDARD_ARGS(<name> ... )
#
# This function is intended to be used in FindXXX.cmake modules files.
# It handles the REQUIRED, QUIET and version-related arguments to FIND_PACKAGE().
# It also sets the <UPPERCASED_NAME>_FOUND variable.
# The package is considered found if all variables <var1>... listed contain
# valid results, e.g. valid filepaths.
#
# There are two modes of this function. The first argument in both modes is
# the name of the Find-module where it is called (in original casing).
#
# The first simple mode looks like this:
# FIND_PACKAGE_HANDLE_STANDARD_ARGS(<name> (DEFAULT_MSG|"Custom failure message") <var1>...<varN> )
# If the variables <var1> to <varN> are all valid, then <UPPERCASED_NAME>_FOUND
# will be set to TRUE.
# If DEFAULT_MSG is given as second argument, then the function will generate
# itself useful success and error messages. You can also supply a custom error message
# for the failure case. This is not recommended.
#
# The second mode is more powerful and also supports version checking:
# FIND_PACKAGE_HANDLE_STANDARD_ARGS(NAME [REQUIRED_VARS <var1>...<varN>]
# [VERSION_VAR <versionvar>
# [CONFIG_MODE]
# [FAIL_MESSAGE "Custom failure message"] )
#
# As above, if <var1> through <varN> are all valid, <UPPERCASED_NAME>_FOUND
# will be set to TRUE.
# After REQUIRED_VARS the variables which are required for this package are listed.
# Following VERSION_VAR the name of the variable can be specified which holds
# the version of the package which has been found. If this is done, this version
# will be checked against the (potentially) specified required version used
# in the find_package() call. The EXACT keyword is also handled. The default
# messages include information about the required version and the version
# which has been actually found, both if the version is ok or not.
# Use the option CONFIG_MODE if your FindXXX.cmake module is a wrapper for
# a find_package(... NO_MODULE) call. In this case VERSION_VAR will be set
# to <NAME>_VERSION and the macro will automatically check whether the
# Config module was found.
# Via FAIL_MESSAGE a custom failure message can be specified, if this is not
# used, the default message will be displayed.
#
# Example for mode 1:
#
# FIND_PACKAGE_HANDLE_STANDARD_ARGS(LibXml2 DEFAULT_MSG LIBXML2_LIBRARY LIBXML2_INCLUDE_DIR)
#
# LibXml2 is considered to be found, if both LIBXML2_LIBRARY and
# LIBXML2_INCLUDE_DIR are valid. Then also LIBXML2_FOUND is set to TRUE.
# If it is not found and REQUIRED was used, it fails with FATAL_ERROR,
# independent whether QUIET was used or not.
# If it is found, success will be reported, including the content of <var1>.
# On repeated Cmake runs, the same message won't be printed again.
#
# Example for mode 2:
#
# FIND_PACKAGE_HANDLE_STANDARD_ARGS(BISON REQUIRED_VARS BISON_EXECUTABLE
# VERSION_VAR BISON_VERSION)
# In this case, BISON is considered to be found if the variable(s) listed
# after REQUIRED_VAR are all valid, i.e. BISON_EXECUTABLE in this case.
# Also the version of BISON will be checked by using the version contained
# in BISON_VERSION.
# Since no FAIL_MESSAGE is given, the default messages will be printed.
#
# Another example for mode 2:
#
# FIND_PACKAGE(Automoc4 QUIET NO_MODULE HINTS /opt/automoc4)
# FIND_PACKAGE_HANDLE_STANDARD_ARGS(Automoc4 CONFIG_MODE)
# In this case, FindAutmoc4.cmake wraps a call to FIND_PACKAGE(Automoc4 NO_MODULE)
# and adds an additional search directory for automoc4.
# The following FIND_PACKAGE_HANDLE_STANDARD_ARGS() call produces a proper
# success/error message.
#=============================================================================
# Copyright 2007-2009 Kitware, Inc.
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)
INCLUDE(FindPackageMessage)
INCLUDE(CMakeParseArguments)
# internal helper macro
MACRO(_FPHSA_FAILURE_MESSAGE _msg)
IF (${_NAME}_FIND_REQUIRED)
MESSAGE(FATAL_ERROR "${_msg}")
ELSE (${_NAME}_FIND_REQUIRED)
IF (NOT ${_NAME}_FIND_QUIETLY)
MESSAGE(STATUS "${_msg}")
ENDIF (NOT ${_NAME}_FIND_QUIETLY)
ENDIF (${_NAME}_FIND_REQUIRED)
ENDMACRO(_FPHSA_FAILURE_MESSAGE _msg)
# internal helper macro to generate the failure message when used in CONFIG_MODE:
MACRO(_FPHSA_HANDLE_FAILURE_CONFIG_MODE)
# <name>_CONFIG is set, but FOUND is false, this means that some other of the REQUIRED_VARS was not found:
IF(${_NAME}_CONFIG)
_FPHSA_FAILURE_MESSAGE("${FPHSA_FAIL_MESSAGE}: missing: ${MISSING_VARS} (found ${${_NAME}_CONFIG} ${VERSION_MSG})")
ELSE(${_NAME}_CONFIG)
# If _CONSIDERED_CONFIGS is set, the config-file has been found, but no suitable version.
# List them all in the error message:
IF(${_NAME}_CONSIDERED_CONFIGS)
SET(configsText "")
LIST(LENGTH ${_NAME}_CONSIDERED_CONFIGS configsCount)
MATH(EXPR configsCount "${configsCount} - 1")
FOREACH(currentConfigIndex RANGE ${configsCount})
LIST(GET ${_NAME}_CONSIDERED_CONFIGS ${currentConfigIndex} filename)
LIST(GET ${_NAME}_CONSIDERED_VERSIONS ${currentConfigIndex} version)
SET(configsText "${configsText} ${filename} (version ${version})\n")
ENDFOREACH(currentConfigIndex)
_FPHSA_FAILURE_MESSAGE("${FPHSA_FAIL_MESSAGE} ${VERSION_MSG}, checked the following files:\n${configsText}")
ELSE(${_NAME}_CONSIDERED_CONFIGS)
# Simple case: No Config-file was found at all:
_FPHSA_FAILURE_MESSAGE("${FPHSA_FAIL_MESSAGE}: found neither ${_NAME}Config.cmake nor ${_NAME_LOWER}-config.cmake ${VERSION_MSG}")
ENDIF(${_NAME}_CONSIDERED_CONFIGS)
ENDIF(${_NAME}_CONFIG)
ENDMACRO(_FPHSA_HANDLE_FAILURE_CONFIG_MODE)
FUNCTION(FIND_PACKAGE_HANDLE_STANDARD_ARGS _NAME _FIRST_ARG)
# set up the arguments for CMAKE_PARSE_ARGUMENTS and check whether we are in
# new extended or in the "old" mode:
SET(options CONFIG_MODE)
SET(oneValueArgs FAIL_MESSAGE VERSION_VAR)
SET(multiValueArgs REQUIRED_VARS)
SET(_KEYWORDS_FOR_EXTENDED_MODE ${options} ${oneValueArgs} ${multiValueArgs} )
LIST(FIND _KEYWORDS_FOR_EXTENDED_MODE "${_FIRST_ARG}" INDEX)
IF(${INDEX} EQUAL -1)
SET(FPHSA_FAIL_MESSAGE ${_FIRST_ARG})
SET(FPHSA_REQUIRED_VARS ${ARGN})
SET(FPHSA_VERSION_VAR)
ELSE(${INDEX} EQUAL -1)
CMAKE_PARSE_ARGUMENTS(FPHSA "${options}" "${oneValueArgs}" "${multiValueArgs}" ${_FIRST_ARG} ${ARGN})
IF(FPHSA_UNPARSED_ARGUMENTS)
MESSAGE(FATAL_ERROR "Unknown keywords given to FIND_PACKAGE_HANDLE_STANDARD_ARGS(): \"${FPHSA_UNPARSED_ARGUMENTS}\"")
ENDIF(FPHSA_UNPARSED_ARGUMENTS)
IF(NOT FPHSA_FAIL_MESSAGE)
SET(FPHSA_FAIL_MESSAGE "DEFAULT_MSG")
ENDIF(NOT FPHSA_FAIL_MESSAGE)
ENDIF(${INDEX} EQUAL -1)
# now that we collected all arguments, process them
IF("${FPHSA_FAIL_MESSAGE}" STREQUAL "DEFAULT_MSG")
SET(FPHSA_FAIL_MESSAGE "Could NOT find ${_NAME}")
ENDIF("${FPHSA_FAIL_MESSAGE}" STREQUAL "DEFAULT_MSG")
# In config-mode, we rely on the variable <package>_CONFIG, which is set by find_package()
# when it successfully found the config-file, including version checking:
IF(FPHSA_CONFIG_MODE)
LIST(INSERT FPHSA_REQUIRED_VARS 0 ${_NAME}_CONFIG)
LIST(REMOVE_DUPLICATES FPHSA_REQUIRED_VARS)
SET(FPHSA_VERSION_VAR ${_NAME}_VERSION)
ENDIF(FPHSA_CONFIG_MODE)
IF(NOT FPHSA_REQUIRED_VARS)
MESSAGE(FATAL_ERROR "No REQUIRED_VARS specified for FIND_PACKAGE_HANDLE_STANDARD_ARGS()")
ENDIF(NOT FPHSA_REQUIRED_VARS)
LIST(GET FPHSA_REQUIRED_VARS 0 _FIRST_REQUIRED_VAR)
STRING(TOUPPER ${_NAME} _NAME_UPPER)
STRING(TOLOWER ${_NAME} _NAME_LOWER)
# collect all variables which were not found, so they can be printed, so the
# user knows better what went wrong (#6375)
SET(MISSING_VARS "")
SET(DETAILS "")
SET(${_NAME_UPPER}_FOUND TRUE)
# check if all passed variables are valid
FOREACH(_CURRENT_VAR ${FPHSA_REQUIRED_VARS})
IF(NOT ${_CURRENT_VAR})
SET(${_NAME_UPPER}_FOUND FALSE)
SET(MISSING_VARS "${MISSING_VARS} ${_CURRENT_VAR}")
ELSE(NOT ${_CURRENT_VAR})
SET(DETAILS "${DETAILS}[${${_CURRENT_VAR}}]")
ENDIF(NOT ${_CURRENT_VAR})
ENDFOREACH(_CURRENT_VAR)
# version handling:
SET(VERSION_MSG "")
SET(VERSION_OK TRUE)
SET(VERSION ${${FPHSA_VERSION_VAR}} )
IF (${_NAME}_FIND_VERSION)
IF(VERSION)
IF(${_NAME}_FIND_VERSION_EXACT) # exact version required
IF (NOT "${${_NAME}_FIND_VERSION}" VERSION_EQUAL "${VERSION}")
SET(VERSION_MSG "Found unsuitable version \"${VERSION}\", but required is exact version \"${${_NAME}_FIND_VERSION}\"")
SET(VERSION_OK FALSE)
ELSE (NOT "${${_NAME}_FIND_VERSION}" VERSION_EQUAL "${VERSION}")
SET(VERSION_MSG "(found suitable exact version \"${VERSION}\")")
ENDIF (NOT "${${_NAME}_FIND_VERSION}" VERSION_EQUAL "${VERSION}")
ELSE(${_NAME}_FIND_VERSION_EXACT) # minimum version specified:
IF ("${${_NAME}_FIND_VERSION}" VERSION_GREATER "${VERSION}")
SET(VERSION_MSG "Found unsuitable version \"${VERSION}\", but required is at least \"${${_NAME}_FIND_VERSION}\"")
SET(VERSION_OK FALSE)
ELSE ("${${_NAME}_FIND_VERSION}" VERSION_GREATER "${VERSION}")
SET(VERSION_MSG "(found suitable version \"${VERSION}\", required is \"${${_NAME}_FIND_VERSION}\")")
ENDIF ("${${_NAME}_FIND_VERSION}" VERSION_GREATER "${VERSION}")
ENDIF(${_NAME}_FIND_VERSION_EXACT)
ELSE(VERSION)
# if the package was not found, but a version was given, add that to the output:
IF(${_NAME}_FIND_VERSION_EXACT)
SET(VERSION_MSG "(Required is exact version \"${${_NAME}_FIND_VERSION}\")")
ELSE(${_NAME}_FIND_VERSION_EXACT)
SET(VERSION_MSG "(Required is at least version \"${${_NAME}_FIND_VERSION}\")")
ENDIF(${_NAME}_FIND_VERSION_EXACT)
ENDIF(VERSION)
ELSE (${_NAME}_FIND_VERSION)
IF(VERSION)
SET(VERSION_MSG "(found version \"${VERSION}\")")
ENDIF(VERSION)
ENDIF (${_NAME}_FIND_VERSION)
IF(VERSION_OK)
SET(DETAILS "${DETAILS}[v${VERSION}(${${_NAME}_FIND_VERSION})]")
ELSE(VERSION_OK)
SET(${_NAME_UPPER}_FOUND FALSE)
ENDIF(VERSION_OK)
# print the result:
IF (${_NAME_UPPER}_FOUND)
FIND_PACKAGE_MESSAGE(${_NAME} "Found ${_NAME}: ${${_FIRST_REQUIRED_VAR}} ${VERSION_MSG}" "${DETAILS}")
ELSE (${_NAME_UPPER}_FOUND)
IF(FPHSA_CONFIG_MODE)
_FPHSA_HANDLE_FAILURE_CONFIG_MODE()
ELSE(FPHSA_CONFIG_MODE)
IF(NOT VERSION_OK)
_FPHSA_FAILURE_MESSAGE("${FPHSA_FAIL_MESSAGE}: ${VERSION_MSG} (found ${${_FIRST_REQUIRED_VAR}})")
ELSE(NOT VERSION_OK)
_FPHSA_FAILURE_MESSAGE("${FPHSA_FAIL_MESSAGE} (missing: ${MISSING_VARS}) ${VERSION_MSG}")
ENDIF(NOT VERSION_OK)
ENDIF(FPHSA_CONFIG_MODE)
ENDIF (${_NAME_UPPER}_FOUND)
SET(${_NAME_UPPER}_FOUND ${${_NAME_UPPER}_FOUND} PARENT_SCOPE)
ENDFUNCTION(FIND_PACKAGE_HANDLE_STANDARD_ARGS _FIRST_ARG)